Activity Trends in the Propane Dehydrogenation Reaction Catalyzed by MIII Sites on an Amorphous SiO2 Model: A Theoretical Perspective

One class of particularly active catalysts for the Propane Dehydrogenation (PDH) reaction are well-defined M(III) sites on amorphous SiO2. In the present work, we focus on evaluating the catalytic trends of the PDH for four M(III) single-sites (Cr, Mo, Ga and In) on a realistic amorphous model of SiO2 using density functional theory-based calculations and the energetic span model. We considered a catalytic pathway spanned by three reaction steps taking place on selected M-III-O pair of the SiO2 model: sigma-bond metathesis of propane on a M-III-O bond to form M-propyl and O-H group, a beta-H transfer step forming M-H and propene, and the H-H coupling step producing H-2 and regenerating the initial M-O bond. With the application of the energetic span model, we found that the calculated catalytic activity for Ga and Cr is comparable to the ones reported at the experimental level, enabling us to benchmark the model and the methodology used. Furthermore, results suggest that both In(III) and Mo(III) on SiO2 are potential active catalysts for PDH, provided they can be synthesized and are stable under PDH reaction conditions.

Automated summary

The study focuses on evaluating the catalytic trends of PDH for four M(III) single-sites on amorphous SiO2, finding that Ga and Cr show comparable catalytic activity to experimental levels, serving as benchmarks for the model and methodology used. Additionally, In(III) and Mo(III) on SiO2 are identified as potential active catalysts for PDH, provided they can be synthesized and stable under reaction conditions.